Microparticulation of an organic compound brings about extreme increase of surface area. Microparticulation of an organic compound thus provides a merit that properties unique to the substance are exhibited readily. Also, in a case where particles are of a poorly soluble or insoluble substance, microparticles formed by microparticulation of the particles can be put in a state of pseudo-dissolution in a solvent such as water (a state where the microparticles, although being suspended in the solvent, appear to be pseudo-dissolved due to the lack of light scattering).
As a conventional microparticulation method, there is known the method disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-113159). This Publication discloses a method of producing microparticles of an organic compound by illumination by a laser light. With this method, organic pigments and condensed polycyclic aromatic compounds, having properties intermediate to those of inorganic substances and organic substances and having rigid and tough molecular structures, are subjected as organic compounds to microparticulation. Microparticulation of organic compounds by laser light illumination is also described in Non-Patent Documents 1 to 3.    Patent Document 1: Japanese Patent Application Laid-Open No. 2001-113159    Non-Patent Document 1: Y. Tamaki et al., “Tailoring nanoparticles of aromatic and dye molecules by excimer laser irradiation,” Applied Surface Science Vol. 168, p. 85-88 (2000)    Non-Patent Document 2: Y. Tamaki et al., “Nanoparticle Formation of Vanadyl Phthalocyanine by Laser Ablation of Its Crystalline Powder in a Poor Solvent,” J. Phys. Chem. A 2002, 106, p. 2135-2139 (2002)    Non-Patent Document 3: B. Li et al., “Enhancement of organic nanoparticle preparation by laser ablation in aqueous solution using surfactants,” Applied Surface Science Vol. 210, p. 171-176 (2003)